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Roger Weller, geology instructor

Crystal Roe
Physical Geology
Fall 2005

Man-Made Diamonds



On February 15, 1955 General Electric Company announced to the world that it had successfully created a

diamond. A scientist working for GE by the name of Dr. Tracy Hall discovered that he could make diamonds

and duplicate the process to create more. GE began by using a large room-sized 400-ton press to put carbon

under extreme high pressure to make diamond dust and chips. . The material was not pure enough or large

enough for gems or digital technology, it did however have other uses such as diamond tipped saws which

made it possible to cut granite countertops and other hard materials. Companies and inventors have spent

the following decades trying to make lager and more pure diamonds. In the 1990’s researchers were focused

on two paths to diamonds Brute force and Chemical Vapor Deposition.


Two ways of making Diamonds

Brute Force

          The Gemesis Company in Sarasota, Florida whom began its operation by purchasing 3 machines from Russia

has been working on and perfecting this procedure in a warehouse with about two dozen washer sized machines.

These machines use a mixture of temperature and pressure to grow diamonds from a small “diamond seed” (a small

sliver of natural diamond). Inside the chamber the seed is bathed in a molten solution of graphite and a proprietary

metal-based catalyst at 1,500 degrees Celsius and 58,000 atm of pressure. The carbon slowly precipitates onto the

diamond seed in less than three and a half hours a 2.8-carat rough yellow diamond (gem quality) grows this size of

diamond can yield a gem larger than 1.5-carat cut and polished.

Giacomo Marchesi
Giacomo Marchesi
Ceramic growth chamber

1.       Put metal solvents and graphite in ceramic
growth chamber. Insert diamond seed (Diamond
chip or dust) at bottom of chamber and put growth
chamber in center of compression sphere.

. Push oil into top layer of sphere, creating pressure against steel anvils. Intense pressure is transferred through anvils and onto growth chamber. Even with minimal pressure at surface, force at center reaches 58,000 atmospheres.

Giacomo Marchesi
carbon atoms
Giacomo Marchesi

3. Turn on a current wired to one end of ceramic chamber which will raises temperature to 2,300 degrees Fahrenheit. Heat and pressure cause graphite - pure carbon - to atomize. Freed carbon drawn to cooler end of chamber bonds to diamond seed, crystallizing layer by layer.

4. Wait for about 36 hours or 3 days or more.

5. Take out growth chamber and smash it, pull out stone. Cut and polish to make sparkling diamond gem.


Giacomo Marchesi
Giacomo Marchesi



IN THE ROUGH To grow its gem-quality yellow diamonds (a rough one is shown above), Gemesis uses washing-machine-sized crystal-growing chambers to reproduce the high pressures and high temperatures that nature relies on. GEMESIS PHOTOS





Chemical Vapor Deposition

          The Apollo Company has focused on Chemical Vapor Deposition or CVD a combination of carbon gases,

temperature and pressure that recreates the environment diamonds were original created under thousands of

years ago. Atoms from the vapor land on a diamond chip placed the chamber. The vapor particles attach to the

structure of the diamond growing the diamond atom by atom into a considerably larger diamond. This process

can make diamonds that are clear and utterly pure. The CVD process can be manipulated by putting boron to

allow the diamond to conduct a current which allows the diamond to become a conductor.




“LET IT RAIN To make diamond by chemical vapor deposition, hydrogen gas and methane are flowed through a chamber containing a substrate. Heat or a microwave-generated plasma is used to split hydrogen gas into atomic hydrogen, which then reacts with methane to give methyl radical and hydrogen gas. The carbon-containing radical species eventually deposit as diamond onto the substrate.”  Joshua Davis.

Photo by Joshua Davis


1. Place diamond wafers on pedestal. Depressurize chamber to one-tenth of an atmosphere.

2. Inject
hydrogen, natural gas (CH4) into chamber add heat using a microwave beam. At 1,800 degrees
Fahrenheit, electrons separate from nuclei, forming plasma.

Giacomo Marchesi

3. Let it rain.
Freed carbon precipitates out of plasma cloud
and is deposited on wafer seeds.

Giacomo Marchesi

4. Let it grow. Wafer seeds gradually become diamond minibricks, building up at half a millimeter a day.

Giacomo Marchesi

5. Open chamber and remove diamond brick.
Slice into wafers for semiconductors or cut and
polish to make gems. (Joshua Davis)

Giacomo Marchesi

Future of Diamonds and possibilities

            The possibilities for man-made diamonds are endless this material is the hardest; it will expand in heat

and will not deteriorate and is chemically inert and optically transparent. The use of man-made diamonds is endless

and it has been said that this invention can revolutionize the industrial world like steel and transistors did decades ago.



          The introduction of the man-made diamond into the mined diamond market has caused a serious reaction by

the number one mined diamond dealer in the world the DeBeers cartel. The cartel has implemented the Gem Defensive

Program in which testing machines have been sent out to the largest national gem laboratories. Traditionally these

laboratories have been used to certify and analyze color, clarity and size now they are being asked to distinguish

between a mined diamond and a man-made diamond. These has proven to be a most difficult feat as both diamonds

have the same chemical make up and reflect light in the same way. There has not been a proven 100 percent method

of distinguishing one from the other.

            The DeBeers cartel and the Jewelers Vigilance Committee have pressured the Federal Trade Commission to

force companies like Gemesis and Apollo to label their man-made diamonds as synthetic. Gemesis is currently

developing a marketing campaign in which the diamonds are called “cultured-diamonds”  hoping that the public

would be more willing to except these diamonds as they do the cultured pearl the campaign it to intice the customer

to buy the man-made diamond and make them sound almost superior to mined diamonds.



            The idea of being able to use diamonds as optical storage will allow the use of lasers to store data in 3D

patterns, cramming huge amounts of information in tiny space. The use of a diamond wafers as a replacement to

silicon ones in computers will allow scientist makes microchips which run even faster and heat conduction in no

longer an issue.



Yarnell, Amanda The Many Facets of Man-Made Diamonds Chemical and Engineering News, Cover Story,

Davis, Joshua The New Diamond Age Wired Magazine

Maney, Kevin Man-made diamonds sparkle with potential USA TODAY

Mulrean, Jennifer Man-made diamonds: a girl's new best friend?  MSN Money


Apollo Diamond

Tracy Hall

Photo Credits: